|Full name||Segundo Alejandro Castillo Nazareno|
|Date of birth||15 May 1982|
|Place of birth||San Lorenzo, Ecuador|
|Height||1.79 m (5 ft 10 1⁄2 in)|
|Playing position||Defensive Midfielder|
|2006–2010||Red Star Belgrade||48||(15)|
|2008–2009||→ Everton (loan)||9||(1)|
|2009–2010||→ Wolverhampton (loan)||8||(0)|
* Senior club appearances and goals counted for the domestic league only and correct as of 26 July 2016.
Segundo Alejandro Castillo Nazareno (born 15 May 1982) is an Ecuadorian international footballer who currently plays for Barcelona Sporting Club of the Ecuadorian Serie A. Castillo is mostly used as a defensive midfielder but can also play as a central midfielder.
Born in San Lorenzo, Esmeraldas, Castillo started his career with Quito's Club Deportivo Espoli spending 3 years with the team, scoring a decent 11 goals in 66 appearances. He then moved across the capital to one of Ecuador's most successful sides Club Deportivo El Nacional, with whom he won successive league titles in 2005 and 2006. He again scored 11 goals in 112 matches for the club.
In August 2006 he moved abroad, signing a two-year deal with Serbian side Red Star Belgrade. He scored 8 goals during his first season at his new club and was a key player when the team won the double in 2007. In total he scored 18 goals in 72 games, an average of a goal every four games.
In August 2008 Castillo joined English Premier League club Everton on a year-long loan deal to become Everton's second signing of the summer transfer window. He made his league debut on 14 September 2008 against Stoke City. He scored his only goal for the Toffees on his home debut against Standard Liège on 18 September 2008 in a UEFA Cup tie with a powerful volley from 25 yards out.
Castillo was not offered a permanent contract by Everton at the conclusion of his loan spell; it was reported that Red Star were asking for around £5 million to make the deal permanent.
Castillo returned to the Premier League once again when he joined newly promoted Wolverhampton Wanderers on a season-long loan on 31 August 2009. He made his Wolves debut against Fulham on 20 September 2009, and had a run of eight appearances before dropping out of the club's first team plans. Castillo received many offers from clubs including LDU Quito and Barcelona On 29 July 2010, It was confirmed that Castillo would return to his home country, Ecuador and play for Deportivo Quito.
Castillo broke into the Ecuadorian national team in 2005, making his international debut on 17 August as a substitute against Venezuela. He became a regular player after this and was included in their squad for the 2006 FIFA World Cup. He played every minute of their World Cup campaign, where Ecuador reached the second round for the first time in their history. He has gained a starting role since the 2006 campaign, mainly as a defensive midfielder and has captained the team in a few occasions.
He scored his first qualifying goal from a second half stoppage time header on 12 October 2012, the third goal in a 3–1 home win against Chile. Castillo was essential to Ecuador's qualifying campaign, netting equalizers that would become crucial points towards qualifying to the 2014 FIFA World Cup, against Venezuela and Argentina.
- Score and Result lists Ecuador's goals first
|1.||24 May 2006||Giants Stadium, East Rutherford, USA||Colombia||1–0||1–1||International Friendly|
|2.||26 March 2008||Estadio La Cocha, Latacunga, Ecuador||Haiti||1–1||3–1||International Friendly|
|3.||20 April 2011||Estadio Jose Maria Minella, Mar del Plata, Argentina||Argentina||2–2||2–2||International Friendly|
|4.||2 September 2011||Estadio Olímpico Atahualpa, Quito, Ecuador||Jamaica||5–1||5–2||International Friendly|
|5.||6 September 2011||Estadio Olímpico Atahualpa, Quito, Ecuador||Costa Rica||3–0||4–0||International Friendly|
|6.||12 October 2012||Estadio Olimpico Atahualpa, Quito, Ecuador||Chile||3–1||3–1||2014 FIFA World Cup qualification|
|7.||16 October 2012||Estadio José Antonio Anzoátegui, Puerto La Cruz, Venezuela||Venezuela||1–1||1–1||2014 FIFA World Cup qualification|
|8.||11 June 2013||Estadio Olímpico Atahualpa, Quito, Ecuador||Argentina||1–1||1–1||2014 FIFA World Cup qualification|
|9.||5 March 2014||The Den, London, England||Australia||2–3||4–3||International Friendly|
- "Players: Squad Profiles: Segundo Castillo". Everton F.C. Retrieved 28 August 2008.
- Ailton i Kastiljo na "Marakani", Politika, 1 September 2006
- Gamble, Matthew (28 August 2008). "Castillo Signing Completed". Everton F.C. Retrieved 28 August 2008.
- "Everton 2–2 Standard Liege". BBC Sport. 18 September 2008. Retrieved 19 September 2008.
- "Everton loan duo looking to seal permanent deals". Liverpool Echo. 29 April 2009.
- "Wolves snap up Ecuador's Castillo". BBC Sport. 31 August 2009.
- "Segundo Castillo Nuevo Jugador Del Deportivo Quito". EcuaFutbol. 29 July 2010.